by Greg Mayer
Matthew Cobb, my fellow guest blogger, has called my attention to a recent paper in Current Biology (abstract only) by Christopher Bird (yes, that’s his name) and Nathan Emery on the behavior of rooks (Corvus frugilegus) that was covered by the BBC and the Times. There’s also a video on the Current Biology website (both this and the BBC video are behaving badly, but the Times‘ is working for me).
What Bird and Emery have shown is that rooks will add stones to a tube of water, raising the water level, so they can reach the water to drink it. As many have noted, this corresponds quite closely to Aesop’s fable of the crow and the pitcher. This shows a remarkable cognitive ability, which seems actually insightful. Crows and their relatives, especially ravens, have been the subject of much recent research showing that they have quite impressive intelligences. The work of Bernd Heinrich (see, for example, his Mind of the Raven) is especially notable.
I should note here that unlike America, which has one common species of crow (Corvus brachyrhynchos; link is from a great site maintained by the Cornell Laboratory of Ornithology), Britain has several species of crows, including the rook, the jackdaw, and the chough (the latter not actually very common, but I like the sound of its name; links from another great site from the Royal Society for the Protection of Birds— h/t to Matthew). Several species also occur in Greece, so Aesop’s fable may have applied to rooks. Ravens are basically large-bodied crows; the common raven, Corvus corax, is found throughout much of the northern hemisphere.